1. Field of the Invention
This invention relates to security systems and more particularly it concerns novel arrangements for recording and checking security tours made by watchmen.
2. Description of the Prior Art
In carrying out security checking operations in factories or other commercial establishments, watchmen usually follow a prearranged tour so that critical areas are checked at predetermined intervals and so that a complete coverage of the premises can be ensured. It is important for insurance and other purposes to have a record made of the watchman's tour. In the past this was obtained by providing the watchman with a self-contained recording unit which included a clock and a disc shaped paper which was rotated by the clock. The recording unit was "punched" or connected to special station keys at preselected locations along the watchman's tour. As each punch was made, the key would make an impression on the paper disc. This impression was in the form of a symbol which corresponded to the identity of the station; and the location of the symbol on the disc, which was rotated by the clock, would correspond to the time that station was checked. After the tour had been completed, the paper disc would be removed from the unit and replaced by a new one. By noting the symbols and their locations on the disc, it was possible to ascertain what stations were checked and at what times and in what order they were checked.
While this system provided a permanent record of the watchman's tour, it was limited, from a practical standpoint, to relatively simple tours involving a small number of stations. Where a greater number of stations are involved the process of checking the recorded discs becomes very time consuming and subject to error. Also, the system does not lend itself to the checking of multiple tours, nor is it readily adaptable to tour modifications.
It has been proposed to utilize electronic means and a computer system to overcome the above described limitations of the conventional watchman's clock system. Such proposals are found, for example, in U.S. Pat. Nos. 1,919,007; 2,275,981; 2,308,198; 2,734,791; 3,237,183; 3,371,349 and 3,736,561. These electronic means, however, involved the wiring of each station to be checked to a central computer. While these electronic systems would produce an instantaneous computer readable indication of each station check made by a watchman, they suffer from the disadvantage that the wiring involved makes them quite expensive. Also, a wired system does not lend itself to tour modification.
In another invention, described and claimed in U.S. application Ser. No. 504,765 filed, Sept. 10, 1974 it is possible to provide one or several tours convering a great number of stations; and these tours may be reported and checked accurately and rapidly with computer means.
According to the last mentioned invention there is provided a tour recording arrangement which is carried in a watchman's unit. This tour recording arrangement includes a clock signal producing means, a station identification signal producing means, a signal storage or memory device and means for directing corresponding clock and station identification signals to predetermined locations in the memory device each time the watchman connects the unit to a station being checked. Unlike the clock rotated paper disc units of the prior art, the clock signals in this last mentioned invention are recorded as actual data in predetermined locations in the memory device. Thereafter, at the end of a tour the watchman's unit may simply be plugged into a terminal and the data stored in its memory device can be read out to provide a complete, accurate and instantaneous report of the tour along with an indication of missed or improperly checked stations or stations checked at the wrong time.
According to one embodiment of this last mentioned invention, the station identification signals direct the clock signals to corresponding locations in the memory device. In another embodiment, the memory device is of sufficient capacity to receive and store both clock signals and station identification signals. In this second embodiment there are provided sequencing means which, upon each station check directs the station identification and clock signals to corresponding locations in the memory device.